people dont steal because they are not a thief, not because of a belief they have. a thief is a thief in their heart - it is a part of who they are as a person. as a christian, if you are a thief you are to admit it and seek god to change you. as an atheist, i dont know what you do. i do know a leopard cant change its own spots, so he would have to seek help from somewhere.
an atheist is and atheist by choice, same as a christian is a christian by choice. and it is as valid a choice as christianity. morality and personality have nothing to do with it. a moral and lawful path in life is as much an intelligent choice for a non-believer as anyone else. it certainly has its rewards here on earth, not the least of which is less stress!
and by the way, mr superhero, you do live in a society of non-believers. most christians are faking it.